The present invention relates to apparatus for attaching a buffer stop or bumping post to railroad track. It has been known for a long time to provide a bumping post or buffer stop at the end of a length of railroad track for serving as an emergency stop in the event a train or railroad car fails to stop in the intended manner due to mistake or equipment failure.
The known buffer stops may be of the type which are intended to slide along a track after being engaged by a railcar, or of the type which are intended to resist the impact of a moving railcar which engages the buffer stop without sliding along the track. In applications of the sliding buffer type, which are most often used in Europe, a sufficient length of extra track is provided to accommodate sliding movement of the buffer from its fixed position. In applications where such extra track is not available, which is often the case in the United States, the buffer stop is attached to rail track with the intent that it will remain in a fixed position when engaged by a moving railcar.
It is also known to provide one or more slave units which are mounted behind a buffer stop in spaced relation thereto so when a buffer stop is caused to slide along track due to the impact of a moving railcar, it will be moved into engagement with an adjacent slave unit which will also slide along the track and assist the buffer stop in stopping a moving railcar.
The present invention does not involve a novel buffer stop. Instead, it relates to novel mechanism for attaching a buffer stop to railroad track. Such novel attachment mechanism has application whether it is intended that the buffer stop will be of the sliding type, or whether the buffer stop is intended to remain fixed when impacted by a moving railcar.
It is also known to provide apparatus for attaching a buffer stop to railroad track. Such known apparatus includes a pair of shoes which at their lower ends engage opposite sides of a rail and upper ends which are bolted together and clamped on opposite sides of a bumping post or buffer stop side wall. In the foregoing manner, a bumping post is attached to the opposed pair of shoes, and the shoes are held by friction to the rail, so that the bumping post is attached to the rail. As noted above, such attachment may be intended to permit the bumping post to slide along the rail on impact from a moving railcar, or it may be intended to hold the bumping post fixed on the rail when impacted by a moving railcar to be stopped.
Still referring to known apparatus for securing a bumping post or buffer stop to rail track, such apparatus includes a pair of opposed shoes which are mounted on opposite sides of a buffer stop side wall, with their lower ends engaged firmly against opposite sides of a rail, and bolts are used to tighten the shoes against the opposite sides of the buffer stop side wall while at the same time tightening the lower ends of the shoes against the rail to obtain a predetermined tightness against the rail. The prior art teaches the use of a torque wrench which measures torque for tightening the bolts referred to above. It is common to provide three bolts for tightening each pair of opposed shoes to secure a buffer stop to a rail. It is also common to provide a plurality such as three sets of shoes for attaching each side wall of a buffer stop to a corresponding rail.
In the foregoing example, if three sets of opposed shoes are provided for each side of a buffer stop, and if three bolts are provided to attach each pair of shoes, nine bolts per side will be required or a total of 18 bolts to attach a buffer stop to rail. The number of bolts is important because it determines the time and effort required to attach a buffer stop to a rail. In this respect, it should be noted that when a sliding buffer has been caused to slide from its normal position due to impact from a moving railcar, it must be repositioned in its original location which requires using the usual torque wrench to properly retighten each of the bolts after loosening the same and repositioning the buffer stop.
One feature of the present invention eliminates the need for using torque wrenches by providing a novel spring pack associated with each of the bolts which tighten a pair of shoes against an opposite side of a buffer side wall. The foregoing feature permits an operator to tighten the bolts to a predetermined tightness with more accuracy and with less time and effort than when the known torque wrenches are used to obtain a predetermined tightness.
Another feature of the present invention comprises a pair of longitudinal wear strips which are riveted to each of a pair of opposing shoes at the inside lower ends thereof which shoes engage against a rail along spaced longitudinal strips thereof. Thus, the tighter the bolts are tightened to clamp a pair of opposed shoes against the opposite sides of a bumper stop side wall, the tighter will be the engagement between the lower ends of such shoes and the rail. In such applications, the shoes will engage the rail only by means of the longitudinal wear strips attached to each shoe. Such wear strips are preferably made of bronze or other metal dissimilar to the rail, and they may be replaced when undue wear occurs.
The foregoing and other objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings.